The present invention relates to video decoding, and more particularly, to an apparatus and method for palette decoding.
The conventional video coding standards generally adopt a block based coding technique to exploit spatial and temporal redundancy. For example, the basic approach is to divide a source frame into a plurality of blocks (or coding units), perform intra prediction/inter prediction on each block, transform residues of each block, and perform quantization and entropy encoding. Besides, a reconstructed frame is generated to provide reference pixel data used for coding following blocks. For certain video coding standards, in-loop filter(s) may be used for enhancing the image quality of the reconstructed frame. A video decoder is used to perform an inverse operation of a video encoding operation performed by a video encoder.
The screen content may be a computer generated content that includes text, graphics and animations. For example, the screen content may be used in applications such as desktop sharing, video conferencing, social networks and remote education. Coding of the screen content should be different from that of a photographic content due to the fact that coding techniques that are proposed for captured image content cannot provide best coding efficiency for screen content. When the screen content is encoded at a video encoder by using a different coding tool (e.g., palette coding) other than that is being used for captured image content, there is a need for a proper decoding scheme (e.g., palette decoding) in a video decoder for reconstructing the screen content.